Marine Weather and Tide Forecast for Taunton, MA

NEAR TERM /UNTIL 6 AM SATURDAY MORNING/
Key Messages:

Key Messages:

* Isolated showers and storms possible late afternoon-early evening, mainly for western MA and CT.

* Low clouds and patchy fog develop tonight.

Clouds have scattered out in most spots this afternoon which has helped support some marginal instability. SPC mesoanalysis shows around 500 J/kg of MLCAPE across west and central MA. Although lacking in much forcing, this should be enough to support the risk for a isolated shower or storm in those mentioned areas late this afternoon through early evening.

Main story for tonight will be low clouds and patchy fog. Similar conditions to last night with a moist airmass and light winds to support the re-development of low stratus and areas of patchy fog.
Can't rule out an isolated shower or sprinkle overnight.

SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/
Key Messages:

* Fog and stratus develop again tonight, and it may linger for quite a while into Saturday.

* Possible round of scattered t-storms Saturday morning in most areas.

* Better chance at t-storms between 2-8 PM west of Worcester.
Some could become strong.

Details:

An upper level low and trough slowly approaches southern New England from the Great Lakes region. This will generate better synoptic support for ascent across the region. The already moist airmass will provide a primed environment for convective showers and thunderstorms and potentially even a couple strong to severe ones later on in the day.

The forecast is (lack of a better word) "messy" for tomorrow. This owes to the very marginally unstable and sufficiently moist airmass that prevails Friday night and Saturday. High resolution guidance has been having difficulty in resolving showers/storms accurately in timing/location over the past few days. Given this marginal airmass, it hasn't taken much to trigger a shower or storm with a little bit of instability and weak lift. The suite of high resolution guidance continues to lack consensus among each other with the details of the convection on Saturday (timing, location). Some models show the potential for some elevated showers and storms in the morning on Saturday over portions of southern New England with lightning and brief heavy downpours as the main threat.

The next element to consider will be how well we clear out. Most model guidance shows that the morning low stratus will be slow/gradual to improve with breaks in the clouds developing in the afternoon across west and central southern New England. This means it will take time for instability to build. If we can break the cloud cover enough, models show a favorable environment for thunderstorms and a couple strong to severe storms as well. If clouds stick around too long, we may not destabilize in time for peak heating while ahead of the approaching cold front.

This has been signaled pretty consistently among the CSU, NSSL ML guidance. Moisture is plentiful with decent boundary layer moisture as well given dewpoints in the low to mid 60s. As a cold front approaches from the west, this will steepen the mid- level lapse rates and support MLCAPE values in the 500-1100 J/kg range across west and central southern New England. Sufficient shear as well, especially later in the afternoon as a low level just pushes in from the west. This should be enough to support multi cell convection with a few of those storms strong to severe with damaging wind and large hail (~1"). Can't rule out the low risk for a tornado as well with low LCLs, steep low level lapse rates, and sufficient 0-1 helicity.

Another element to the "messier" forecast will be the timing of the convection. There isn't a lot of agreement among high resolution guidance on the timing of the convection. Overall, there will be a round or two of thunderstorms that develop across western southern New England mid afternoon through early evening. The second round of storms will likely hold the greater risk for severe with the HRRR showing a line developing across western MA early evening moving eastward. So bottom line, the risk for thunderstorms in west and central New England increases in the afternoon with the higher chance for seeing strong to severe storms late afternoon-early evening. It is that time of year where there are plenty of outdoor events, so stay updated on the forecast and stay aware of incoming weather.

LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/
Key Messages

* Mild day Sunday with a risk for some scattered showers across interior southern New England

* Warm/dry day on Monday with seasonable temperature

* Trending cooler Tuesday through the end of next week with daily highs/lows in the upper 50s/lows and mid to upper 40s respectively

* Mid-week coastal storm may bring substantial precipitation and gusty winds to southern New England.

Sunday and Monday

An upper-level low moves over southern New England on Sunday. Cold pool aloft and some elevated instability may produce a few scattered showers in the afternoon mainly across the interior of southern New England. Otherwise expecting mild temperatures in the upper 60s-low 70s. The associated upper trough axis shifts east of southern New England Sunday night into Monday supporting height rises and a dry/mild day on Monday with seasonable high temperatures in the upper 60s to low 70s.

Tuesday

As the aforementioned upper-level low shifts east of southern New England Monday into Tuesday, a deep northwest flow pattern develops over southern New England. This will support cooler/drier conditions on Tuesday with high temperatures likely confined to the low 60s and perhaps mid 60s in the CT River Valley.

Wednesday - Friday

By Wednesday, short-wave energy digging south over The Great Lakes will likely support the development of a coastal low-pressure system over The Mid-Atlantic states. This system is forecast to travel up the east coast and produce a late spring Nor'Easter for southern New England. This would mean a period of gusty northeast winds and substantial rainfall. Model guidance differs on the timing with some ensemble members supporting a faster solution that would result in a wet Wednesday afternoon. Other members support a late arrival with a mostly dry day Wednesday followed by a wet Wednesday night/Thursday.
As the system departs the region toward the end of next week we'll be left with broad cyclonic flow aloft that will support cool/unsettled weather into next weekend. Stay tuned for more details.

AVIATION /23Z FRIDAY THROUGH WEDNESDAY/
Low - less than 30 percent.
Moderate - 30 to 60 percent.
High - greater than 60 percent.

00Z TAF Update

Tonight: Moderate confidence.

IFR-LIFR ceilings and visibilities return from the coastal waters mainly after 00z. Low chance of an isolated SHRA after 06z.

Saturday: Moderate confidence overall, but lower on timing both sub-VFR improvement and on timing SHRA/TS.

IFR-LIFR stratus likely to begin Sat. Slow improvement late morning through early afternoon with MVFR, improving over the west terminals first then eastward. West terminals improve toward VFR mid afternoon. Lower confidence in timing of further improvements across the east terminals in the afternoon, likely not until late afternoon if it does scatter out. Convective showers/storms possible in the morning 13-16z, but will be isolated- widely scattered. Another round for western airports after 18z and closer to 00z. Timing lower confidence. Some storms could become strong, with a better chance for strong activity in the 2nd round of storms for BAF- BDL- ORH. Winds mainly SE to S around 5-10 kt.

KBOS TAF...Moderate confidence. IFR cigs move in after 03z with lowering visibilities from BR. Slow improvements in ceilings Saturday morning with MVFR cigs. Low chance for convective showers 14-16z around the terminal. SE winds 5-12 kts.

KBDL TAF...Moderate confidence. IFR/LIFR overnight. Gradual improvements after 15z toward MVFR and VFR later in afternoon.
Few rounds of thunderstorms possible in the afternoon and early evening. Timing lower confidence. Few stronger storms possible, more likely with the early evening round of storms.

Outlook /Sunday Night through Wednesday/...

Sunday Night: Mainly VFR, with local MVFR possible. Breezy.
Slight chance SHRA.

Monday: VFR. Breezy.

Monday Night: VFR. Breezy. Slight chance SHRA.

Tuesday: VFR. Breezy.

Tuesday Night: Mainly VFR, with areas MVFR possible.

Wednesday: MVFR/IFR conditions possible. Chance SHRA.

MARINE
Forecaster Confidence Levels:

Low - less than 30 percent.
Medium - 30 to 60 percent.
High - greater than 60 percent.

High confidence overall.

Fog and reduced visibility will be the biggest potential hazard for mariners tonight, with S winds around 10 kt and seas 4 ft or less. Risk for thunderstorms could develop as soon as pre- dawn Saturday over the southern waters, with another round of storms possible into Saturday afternoon. Winds 10-15 kts out of SE Saturday switching to W Saturday night. Waves across southern outer waters increase to 4-5 ft Sunday which will need SCAs as we get closer.

Outlook /Sunday Night through Wednesday/...

Sunday Night: Winds less than 25 kt. Areas of seas approaching 5 ft. Slight chance of rain showers.

Monday: Winds less than 25 kt. Areas of seas approaching 5 ft.

Monday Night: Winds less than 25 kt. Seas locally approaching 5 ft. Slight chance of rain showers.

Tuesday through Tuesday Night: Winds less than 25 kt. Seas locally approaching 5 ft.

Wednesday: Winds less than 25 kt. Areas of seas approaching 5 ft. Slight chance of rain showers.

BOX WATCHES/WARNINGS/ADVISORIES
CT...None.
MA...None.
RI...None.
MARINE...None.